Fermi surface reconstructions and transport spectroscopy in heavy-fermion materials*

Fermi surface (FS) reconstructions lead to pronounced anomalies in thermodynamic and transport properties of heavy-fermion materials. Of particular interest are Electronic Topological (Lifshitz) transitions where the number of FS sheets changes abruptly under the influence of external parameters like chemical doping, pressure, or magnetic field. Lifshitz transitions are generally associated with the presence of critical points in the electronic band structure.

We demonstrate that very detailed information on the electronic structure in the vicinity of critical points can be deduced from high-precision measurements of the Seebeck in heavy-fermion materials which, in turn, may allow for transport spectroscopy when only part of the FS becomes critical. The calculations of the transport anomalies proceed from Renormalized Band (RB) structure calculations and take into account multiple scattering processes between different critical regions in the band structure